W DOC AIRBUS | TSM A320F

Slat System Asymmetry Fault

TASK 27-81-00-810-813-A
Slat System Asymmetry Fault

1. Possible Causes
  • slat transmission assembly
  • POSITION PICK OFF UNIT [31CV]
  • POSITION PICK OFF UNIT [32CV]
2. Job Set-up Information
 A. Fixtures, Tools, Test and Support Equipment
REFERENCE
QTY
DESIGNATION
98D27804012000
1
GAGE-RIGGING
 B. Referenced Information
REFERENCE
DESIGNATION
AMM 27-80-00-866-008
Manual Retraction of the Slats
AMM 27-80-00-869-004
Reset of the Wing Tip Brake (WTB) of the Slat System on the Ground
AMM 27-81-00-820-001
Manual Adjustment of the Position Pick-Off Units
AMM 27-81-18-000-001
Removal of the Asymmetry-Position Pick-Off Unit
AMM 27-81-18-400-001
Installation of the Asymmetry-Position Pick-Off Unit
AMM 27-84-00-200-001
Detailed Visual Inspection of the Slat Transmission System
AMM 27-84-00-710-001
Operational Test of the Slat System
3. Fault Confirmation
Subtask 27-81-00-730-050-A
A. Procedure
   (1) Get access to the MENU Mode and set it to SFCC 1 or SFCC 2.
     (a) Go to submenu SYSTEM DATA SLAT.
     (b) Press the line key 1L to set the PPU page.
NOTE: The SFCC transmits the LH and RH APPU data page(s) to the CFDS. Every 5 seconds the data of the APPU DATA pages(s) will be refreshed.
     (c) In the TSM:
Refer to page block 301 TABLE 2. The LH APPU and RH APPU Synchro Angles are shown as a decimal value.
NOTE: A difference of more than 5.2 deg. generates an asymmetry fault message.
     (d) If there is this difference between the LH and RH APPU values, do the fault isolation.
4. Fault Isolation
Subtask 27-81-00-810-062-A
A. Procedure
   (1) Refer to the PPU DATA to identify the defective wing (refer to the fault confirmation):
  • The APPU Data that is incremented from FPPU and other APPU by more than 5.2 deg. shows the defective wing.
   (2) Do the reset of the wing tip brakes AMM 27-80-00-869-004.
   (3) Do the detailed visual inspection of the slat transmission assembly AMM 27-84-00-200-001.
     (a) Do specially an inspection of the slat transmission shaft connection of the defective wing for rupture and missing flange bolts.
     (b) Repair/correct any failure found (Ref. AMM chap. 27).
   (4) Do the operational test of the slat system, AMM 27-84-00-710-001.
   (5) If the failure continues, do a check of the APPU zero datum mark of the defective wing, AMM 27-81-00-820-001.
     (a) If the zero datum mark is not aligned, remove the applicable APPU, AMM 27-81-18-000-001:
  • visually examine the APPU adapter mounting interface,
  • visually examine the APPU for signs of water thru the sight glass and the input shaft for visible dent.
     (b) If the APPU is found in good condition, do the steps that follow:
       1 With the APPU not installed on the defective wing:
  • Do the manual retraction of the slats on the left and right wing AMM 27-80-00-866-008 until the FPPU shows zero,
  • Put the 98D27804012000 GAGE-RIGGING between the track stop and the lower forward roller at each track 1,
  • Make sure that the 98D27804012000 GAGE-RIGGING contacts the track stop and the lower forward roller.
NOTE: In this condition it is not necessary to use the PPU values recorded before manual extension.
       2 Do the manual adjustment of the APPU AMM 27-81-00-820-001.
   (6) Before the operational test:
     (a) Do the operational test of the slat system AMM 27-84-00-710-001.
   (7) Get access to the SLT ON GROUND FAULTS page and make sure that there are no faults.
5. Close-up
Subtask 27-81-00-942-062-A
A. Remove the ground support and maintenance equipment, the special and standard tools and all other items.
Subtask 27-81-00-860-063-A
B. Put the aircraft back to its initial configuration.
[Rev.8 from Aug 2018] 2026.04.04 04:27:48 UTC
"WTRUIB" 2025